Inhibition Of Nitric Oxide Production Research Articles

Alkaloids and Styryl Lactones from Goniothalamus tortilipetalus and Their Biological Activities.

Phytochemical investigations of the twig and leaf extracts of Goniothalamus tortilipetalus resulted in the isolation and identification of two new alkaloids, goniotortiline (1) and goniotortilactam (2), three new styryl lactone derivatives, goniotortilactone (3) and goniotortilols A (4) and B (5), and 25 known compounds. Their structures were elucidated by spectroscopic methods and HRESITOFMS data. Compounds 5, 13, 15, 16, 22, and 30 inhibited nitric oxide (NO) production with IC50 values ranging from 8.7 ± 0.1 to 17 ± 1 μM, revealing stronger effects than the standard drug, dexamethasone (IC50 16.9 ± 2.2 μM), and compound 30 possessed the most potent NO production inhibition. Compounds 12 and 29 demonstrated notable efficacy in enhancing glucose consumption with IC50 values of 77 ± 4 and 66 ± 4 μM, respectively, while their glucose uptakes were 1.7- and 2-fold, respectively.

Major Sesquiterpenoids in Psychotria laui Leaf Essential oil Exhibit Anti-Inflammatory and Cytotoxic Properties

Objective: This study aims to investigate the chemical constituents and biological properties of the essential oil derived from Psychotria laui, a plant recognized for its medicinal applications, particularly in traditional Vietnamese medicine, where it is utilized for the treatment of digestive and inflammatory disorders. Methods: Fresh leaves of Psychotria laui were gathered in Quangtri, Vietnam, and subjected to hydro-distillation using a Clevenger-type apparatus to obtain the essential oil. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant potential was measured using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay, while the inhibition of nitric oxide production was tested in lipopolysaccharide-stimulated RAW264.7 cells. Cytotoxicity against the SK-LU-1 cell line (human lung adenocarcinoma) was evaluated using the sulforhodamine B (SRB) assay. Results: The essential oil from Psychotria laui contained 78 distinct constituents. The major compounds identified were spathulenol (10.4%), thujopsan-2- α-ol (9.5%), 7- epi- α-eudesmol (6.5%), 14-hydroxy-9- epi-( E)-caryophyllene (4.4%), epi- α-cadinol (3.9%), α-muurolol (3.8%), 1- epi-cubenol (3.5%), and δ-cadinene (3.2%). The essential oil showed no antioxidant activity, with an IC50 (half-maximal inhibitory concentration) value greater than 500 µg/mL, in contrast to the positive control, L-ascorbic acid, which had an IC50 of 7.78 ± 0.39 µg/mL in the DPPH assay. However, its anti-inflammatory activity was evident by its ability to inhibit nitric oxide production, with an IC50 of 19.48 ± 1.53 µg/mL in lipopolysaccharide-stimulated RAW264.7 macrophages. Moreover, the essential oil exhibited potent cytotoxicity against the SK-LU-1 cancer cell line, with an IC50 of 8.49 ± 0.73 µg/mL in the SRB assay. Conclusion: The essential oil from Psychotria laui leaves contains numerous bioactive compounds and exhibits significant anti-inflammatory and cytotoxic properties, although it lacks antioxidant activity.

Simultaneous Quantification of Serum Symmetric Dimethylarginine, Asymmetric Dimethylarginine and Creatinine for Use in a Routine Clinical Laboratory.

Background Symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) are naturally occurring amino acids classed as uremic toxins by the EUTOX working group. SDMA is principally excreted through the kidneys and is a well-known renal function marker, ADMA is a potent inhibitor of nitric oxide production. Here, we describe the development of a rapid and sensitive liquid chromatography tandem mass spectrometry method for simultaneous measurement of SDMA, ADMA and creatinine. Method Serum samples were prepared by protein precipitation and dilution with acetonitrile prior to injection onto a Waters TQS-Micro. Multiple reaction monitoring was used to detect SDMA, ADMA, creatinine, and their corresponding internal standard transitions after separation with a HILIC analytical column. Sample stability and intra-individual variation studies were also assessed following ethical approval. Results The retention time for creatinine was 0.43, SDMA 1.10 and ADMA 1.14 minutes. Mean recovery for creatinine was 103%, SDMA was 100% and ADMA was 103%, matrix effects were minimal (<6%). Lower limit of quantitation for creatinine and SDMA/ADMA was 17.5 µmol/L and 0.1 µmol/L respectively. Analytical imprecision showed a coefficient of variation <10% for all analytes across the working range of the assays. Intra-individual variation for creatinine was 4.7%, SDMA 7.5% and ADMA 7.6%. Discussion We have developed a rapid assay for LC-MS/MS measurement of SDMA, ADMA and creatinine in a routine clinical laboratory. It is simple, reproducible, and easy to perform. The stability of SDMA and ADMA pre- and post-centrifugation allows for their routine use without any special sample handling requirements.

Phyllanretiosides A and B: Two Undescribed Compounds from Phyllanthus Reticulatus with Nitric Oxide Production Inhibition and Antimicrobial Activity.

Phytochemical study on the methanol extract of the leaves of Phyllanthus reticulatus led to the isolation of two new compounds, phyllanretiosides A (1) and B (2) together with ten known ones (3-12). Their chemical structures were determined by HR-ESI-MS, NMR, and ECD spectra in comparison with the literature. Three ellagitannins, phyllanretioside A (1), corilagin (3), and phyllanthusiin C (4) inhibited lipopolysaccharide(LPS)-induced nitric oxide production in RAW 264.7 cells with IC50 values of 63.2, 83.2, and 5.6 μM, respectively. In addition, compounds 1, 3, and 4 exhibited significantly antimicrobial activity (MICs: 16-128 μg/mL) towards some of seven microbial strains.

Mapping the proteomic landscape and anti-inflammatory role of Streptococcus parauberis extracellular vesicles

Bacterial extracellular vesicles (BEVs) are nanoscale membrane-bound structures involved in intercellular communication and transport of bioactive molecules. In this study, we described the proteomic insight and anti-inflammatory activity of Streptococcus parauberis BEVs (SpEVs). Proteomics analysis of SpEVs identified 6209 distinct peptides and 1039 proteins. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated enrichment in pathways related to the biosynthesis of aminoacyl tRNA, amino acids, and secondary metabolites. Based on the predicted protein-protein interactions, we discovered key immunological proteins such as IL12A, IL12B, IL8, CD28, and NF-κB between SpEVs and human proteins. Functionally, SpEVs exhibit strong anti-inflammatory activity in LPS-stimulated Raw 264.7 cells by reducing the production of key inflammatory mediators. These include nitric oxide (NO), reactive oxygen species (ROS), inflammatory cytokines such as TNFα and IL6, as well as inflammation-related proteins like inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). qRT-PCR and immunoblotting results clearly indicate that SpEVs modulate the NF-κB and MAPK pathways to induce anti-inflammatory activity. Furthermore, in vivo experiments with zebrafish larvae demonstrated that SpEVs treatment reduced the NO and ROS production with minimal cell mortality. Finally, we validated the anti-inflammatory activity of SpEVs in vivo by systematically assessing the inhibition of NO production, reduction in ROS generation, prevention of cell death, and modulation of NF-κB and MAPK signaling pathways. In conclusion, SpEVs contain rich in unique proteins that play crucial roles in mediating anti-inflammatory effects.

Synthesis, Characterization and Targeted Drug Delivery of Curcumin-Loaded PLGA Nanoparticles

Background: Nanoparticle-based drug delivery systems have revolutionized therapeutic delivery, offering advantages such as enhanced bioavailability, controlled release, and targeted delivery to diseased tissues. Among these, polymeric nanoparticles, especially those utilizing poly(lactic-co-glycolic acid) (PLGA), have shown significant potential due to their biocompatibility, biodegradability, and stability. Curcumin, a polyphenolic compound with potent anti-inflammatory and anticancer properties, faces clinical limitations due to poor solubility and low bioavailability. Encapsulation in PLGA nanoparticles could enhance curcumin’s therapeutic efficacy by improving stability, controlled release, and targeted delivery. Methods: Curcumin-loaded PLGA nanoparticles were synthesized using a solvent evaporation method. Nanoparticles were characterized using dynamic light scattering (DLS) for size and zeta potential, and scanning electron microscopy (SEM) for morphology. In vitro drug release was assessed using a dialysis method, while cytotoxicity and anti-inflammatory activity were evaluated using MTT and nitric oxide inhibition assays, respectively. Results: DLS analysis revealed an average particle size of 150 ± 10 nm and a zeta potential of -25 ± 2 mV, indicating stability and suitability for therapeutic applications. SEM imaging showed smooth, spherical nanoparticles. Drug release studies displayed a biphasic pattern, with an initial burst followed by sustained release over 72 hours. Cytotoxicity assays demonstrated enhanced anticancer activity of curcumin-loaded nanoparticles compared to free curcumin, with a significantly lower IC50 value (5 ± 0.5 µM versus 15 ± 1.0 µM). Anti-inflammatory studies showed a 60% inhibition of nitric oxide production in LPS-induced macrophages, indicating improved anti-inflammatory efficacy over free curcumin. Conclusion: Curcumin-loaded PLGA nanoparticles show promise as a targeted drug delivery system, with enhanced stability, controlled release, and increased therapeutic efficacy. These findings support further in vivo studies to validate the clinical potential of curcumin nanoparticles in cancer and inflammatory diseases, providing a foundation for advanced therapeutic applications.

Neudesin, a secretory protein, attenuates activation of lipopolysaccharide-stimulated macrophages by suppressing the Jak/Stat1/iNOS pathway

AimsNeudesin, a heme-binding protein previously identified for its neurotrophic activity, has been implicated in various physiological and pathological processes, including immune regulation. However, its role in inflammatory macrophages remains unclear. Herein, we investigated the function of neudesin in the regulation of inflammatory macrophages. Main methodsIn vitro experiments were performed in bone marrow-derived macrophages (BMDMs). In vivo experiments were conducted on neudesin knockout mice with a murine endotoxic shock model. Key findingsWe observed that neudesin deficiency led to elevated expression of Nos2/iNOS and increased nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BMDMs. Further, we found that neudesin, via the ERK/MAPK signaling pathway, promotes the proteasome-mediated degradation of Stat1, resulting in suppression of NO production. Furthermore, neudesin-deficient mice exhibited higher mortality rates following LPS administration, accompanied by increased Nos2/iNOS expression and nitrated proteins in the heart, compared to that in wildtype mice. Treatment with an iNOS inhibitor drastically improved the survival rate of neudesin-deficient mice, highlighting the significance of neudesin-mediated iNOS signaling in modulating immune responses and preventing excessive inflammation. SignificanceOur findings suggest that neudesin acts as an anti-inflammatory cytokine, suppressing NO production in inflammatory macrophages, underscoring its potential as a therapeutic target for immune-related disorders.

Bioprospection of rattlesnake venom peptide fractions with anti-adipose and anti-insulin resistance activity in vitro

Animal venoms are natural products that have served as a source of novel molecules that have inspired novel drugs for several diseases, including for metabolic diseases such as type-2 diabetes and obesity. From venoms, toxins such as exendin-4 (Heloderma suspectum) and crotamine (Crotalus durissus terrificus) have demonstrated their potential as treatments for obesity. Moreover, other toxins such as Phospholipases A2 and Disintegrins have shown their potential to modulate insulin secretion in vitro. This suggests an unexplored diversity of venom peptides with a potential anti-obesogenic in Mexican rattlesnake venoms. For that reason, this study explored the in vitro effect of Crotalus venom peptide-rich fractions on models for insulin resistance, adipocyte lipid accumulation, antioxidant activity, and inflammation process through nitric oxide production inhibition. Our results demonstrated that the peptide-rich fractions of C. aquilus, C. ravus, and C. scutulatus scutulatus were capable of reverting insulin resistance, enhancing glucose consumption to normal control; C. culminatus, C. molossus oaxacus, and C. polystictus diminished the lipid accumulation on adipocytes by 20%; C. aquilus, C. ravus, and C. s. salvini had the most significant cellular antioxidant activity, having nearly 80% of ROS inhibition. C. aquilus, C. pyrrhus, and C. s. salvini inhibited nitric oxide production by about 85%. We demonstrated the potential of these peptides from Crotalus venoms to develop novel drugs to treat type-2 diabetes and obesity. Moreover, we described for the first time that Crotalus venom peptide fractions have antioxidant and inflammatory properties in vitro models.

Modulation of M1/M2 Cytokines and Inflammatory Enzymes by Persicaria Species Leaf Extracts in Lipopolysaccharide-stimulated RAW 264.7 Cell Macrophages.

Investigating the impacts of plant-based substances on the regulation of pro-inflammatory M1 and anti-inflammatory M2 cytokines could have significant implications for immune-related health conditions. Seven Persicaria plant species from sub-Saharan Africa were specifically selected for analysis, based on their traditional use in treating inflammation. To investigate the inhibitory effects of methanol leaf extracts from selected plants on enzymes involved in chronic inflammation. The inhibition of nitric oxide production, acetylcholinesterase activity, and 15-lipoxygenase activity was assessed using the Griess reagent method, Ellman's colorimetric method, and the ferrous oxidation-xylenol orange assay. The quantity of M1/M2 cytokines released was quantified using a flow cytometer. At a concentration of 50 µg/mL, the methanol extracts of P. limbata exhibited the highest NO inhibition (97.67%), followed by P. nepalensis (93.06%) and P. setosula (92.78%). The NO inhibition caused by the plant extracts was correlated directly with the decrease in NO release by the LPS-stimulated macrophages. Furthermore, the pro-inflammatory enzyme assays indicated that the methanol extracts of P. setosula exhibited the highest enzyme inhibitory activity (LOX 89.59%, AChE 72.12 %). This was followed by P. limbata (with 92.76% for LOX and 56.93% for AChE) and P. nepalensis (with 88.16% for LOX and 47.17% for AChE). Cytokine assays revealed that the extracts of P. limbata had significant dose-dependent suppressive effects on IFN-γ and TNF-α expression while promoting the secretion of IL-2, IL-4, IL-6, and IL-10. Extracts of P. limbata contain immunomodulatory compounds that could be further explored as potential remedies to target the molecular drivers of chronic inflammation.

Mechanisms of GTN-induced migraine: Role of NOS isoforms, sGC and peroxynitrite in a migraine relevant mouse model.

Migraine research has highlighted the pivotal role of nitric oxide (NO) in migraine pathophysiology. Nitric oxide donors such as glyceryl trinitrate (GTN) induce migraine attacks in humans, whereas spontaneous migraine attacks can be aborted by inhibiting NO production. The present study aimed to investigate how GTN triggers migraine through its three nitric oxide synthase (NOS) isoforms (neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS)) via a suspected feed-forward phenomenon. Migraine-relevant hypersensitivity was induced by repeated injection of GTN in an in vivo mouse model. Cutaneous tactile sensitivity was assessed using von Frey filaments. Signaling pathways involved in this model were dissected using non-selective and selective NOS inhibitors, knockout mice lacking eNOS or nNOS and their wild-type control mice. Also, we tested a soluble guanylate cyclase inhibitor and a peroxynitrite decomposition catalyst (Ntotal = 312). Non-selective NOS inhibition blocked GTN-induced hypersensitivity. This response was partially associated with iNOS, and potentially nNOS and eNOS conjointly. Furthermore, we found that the GTN response was largely dependent on the generation of peroxynitrite and partly soluble guanylate cyclase. Migraine-relevant hypersensitivity induced by GTN is mediated by a possible feed-forward phenomenon of NO driven mainly by iNOS but with contributions from other isoforms. The involvement of peroxynitrite adds to the notion that oxidative stress reactions are also involved.

METABOLIC SYNDROME: IN VITROANTIOXIDANT, ANTICANCER, ANTI-INFLAMMATORY AND ANTIMICROBIAL ACTIVITIES OF DISSOTIS ROTUNDIFOLIA(SM.) WITH PHYTOCHEMICAL AND NUTRITIONAL COMPONENTS

Background:Dissotis rotundifolia(Sm.) Triana isa prostrate herb of the family Melastomataceae. It is used for the treatment of obesity, hypertension, circulatory problems and metabolic syndrome (MS). This study evaluated the antioxidant, anticancer, anti-inflammatory.and antimicrobial activities of the whole plant of D. rotundifoliato validateits therapeutic potential in the management and treatment of MS. Materials and Methods: The plant was screened for proximate, mineral, vitamin and phytochemical components, as well as antioxidant activities using standard laboratory techniques. The anticancer activities of the ethanol plant extract were against kidney (VERO) and breast (MCF-7) cancer cells. The anti-inflammatory activity of the extract was determined using nitric oxide production inhibition assay and the antimicrobial activity was evaluated against five pathogenic organisms. All data were subjected to statistical analysis. Results: The plant was rich in carbohydrate (47.87%), protein (22.5%), crude fibre (9.57%), Na (206.67 mg/100 g), Ca (183.33mg/100 g), vitamin C (25.53 mg/100 g), flavonoids (685.00 mg/100 g), alkaloids (616.67 mg/100 g) and saponins (471.67 mg/100 g) contents. Theextract exhibited considerableand variedantioxidant activities.The plant extract was very active against VERO and MCF-7 cellsatlow concentrations(0.145 mg/ml and 0.141 mg/ml respectively) compared to doxorubicin. It also exhibited significant anti-inflammatory action against lipopolysaccharide (LPS)-stimulated RAW macrophage. The extract was active against all test organisms. Overall, D. rotundifolia displayed significant antioxidant, anticancer, anti-inflammatory and antimicrobial activities. Conclusion: The observed bioactivities of the plant could be attributed to its phytocontents and are indications of itspotential as an agent for the managementand treatment ofmetabolic syndrome.

Comprehensive phytochemical profiling and biological activities of Hodgsonia heteroclita subsp. indochinensis seed extracts

Hodgsonia heteroclita subsp. indochinensis, a member of the Cucurbitaceae family, is utilized in traditional medicinal remedies based on indigenous wisdom. This study aimed to comprehensively identify and analyze the bioactive phytoconstituents within H. heteroclita subsp. indochinensis seeds. Seeds were sequentially extracted with n-hexane, ethyl acetate, and methanol. Liquid chromatography-mass spectrometry analysis detected ferulic acid, salicylic acid, cucurbitacin E, stigmasterol glucoside, and β-sitosterol glucoside in all extracts. The total phenolic content in the HH(S)-EtOAc and HH(S)-MeOH was 14.22 ± 1.58 and 12.98 ± 1.03 mg gallic acid equivalent/g, respectively. Consequently, the HH(S)-EtOAc demonstrated antioxidant activity with an IC50 of 1.10 ± 0.28 mg/mL, while the HH(S)-MeOH displayed strong antioxidant potential with an IC50 of 0.04 ± 0.00 mg/mL according to an ABTS assay. Antibacterial evaluations of both the HH(S)-hexane and HH(S)-EtOAc revealed significant activity against Staphylococcus aureus (zone of inhibition (ZOI): 13.67 ± 2.31 and 11.67 ± 1.53 mm, respectively) but limited activity against Escherichia coli (ZOI: 7.33 ± 0.58 and 7.67 ± 0.58 mm, respectively). Additionally, the extracts exhibited low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, ranging from 62.50 to 250 mg/mL. The antiproliferative activity of seed extracts was assessed against two breast cancer cell lines (MCF-7 and MDA-MB-231), normal breast cells (MCF10A), and human embryonic kidney (HEK) 293T cells, through MTT and clonogenic assays. The results revealed IC50 values exceeding 400 μg/mL, indicating that the extracts are safe. Furthermore, all seed extracts (50 μg/mL) exhibited potent anti-inflammatory activity, evident by their substantial inhibition of nitric oxide production (p < 0.001) and inducible nitric oxide synthase (iNOS) gene expression (p < 0.05) in LPS-induced RAW264.7. These findings demonstrate the potential for H. heteroclita subsp. indochinensis seed extracts in the development of functional foods, nutraceuticals, and dietary supplements due to their diverse bioactive compounds and substantial biological activities, particularly their anti-inflammatory effects.

Increase of PCSK9 expression in diabetes promotes VEGFR2 ubiquitination to inhibit endothelial function and skin wound healing.

Diabetic foot ulcers (DFUs) are a serious vascular disease. Currently, no effective methods are available for treating DFUs. Pro-protein convertase subtilisin/kexin type 9 (PCSK9) regulates lipid levels to promote atherosclerosis. However, the role of PCSK9 in DFUs remains unclear. In this study, we found that the expression of PCSK9 in endothelial cells (ECs) increased significantly under high glucose (HG) stimulation and in diabetic plasma and vessels. Specifically, PCSK9 promotes the E3 ubiquitin-protein ligase NEDD4 binding to vascular endothelial growth factor receptor 2 (VEGFR2), which led to the ubiquitination of VEGFR2, resulting in its degradation and downregulation in ECs. Furthermore, PCSK9 suppresses the expression and activation of AKT, endothelial nitric oxide synthase (eNOS), and ERK1/2, leading to decreased nitric oxide (NO) production and increased superoxide anion (O2._) generation, which impairs vascular endothelial function and angiogenesis. Importantly, using evolocumab to limit the increase in PCSK9 expression blocked the HG-induced inhibition of NO production and the increase in O2._ production, as well as inhibited the phosphorylation and expression of AKT, eNOS, and ERK1/2. Moreover, evolocumab improved vascular endothelial function and angiogenesis, and promoted wound healing in diabetes. Our findings suggest that targeting PCSK9 is a novel therapeutic approach for treating DFUs.

Evaluation of In Vitro Antihypertensive and Anti-Inflammatory Properties of Dairy By-Products

Sweet whey (SW) and yogurt acid whey (YAW) are dairy by-products of the cheese-making process and Greek-style yogurt production, respectively. Both of them are considered pollutants with huge volumes of SW and YAW produced due to the growing demand for dairy products worldwide. Moreover, whey-derived peptides, resulting from fermentation as well as from further hydrolysis during digestion, have been associated with various biological activities. In the present study, the angiotensin-converting enzyme (ACE)-inhibitory activity of 48 SW samples and 33 YAW samples from bovine, ovine, caprine, and ovine/caprine milk obtained were evaluated. Additionally, the SW and YAW digestates and two of their fractions (smaller than 10 kDa, SW-D-P10 and YAW-D-P10, and smaller than 3 kDa, SW-D-P3 and YAW-D-P3), which were obtained after in vitro digestion and subsequent ultrafiltration, were also subjected to evaluation. Our data indicated that the D-P10 and D-P3 fractions exhibited higher ACE-inhibitory activity compared to the corresponding values before digestion. The ACE-inhibitory capacity after in vitro digestion was higher for the ovine SW samples compared to their bovine and caprine counterparts. The effect of the D-P3 fraction on the inhibition of nitric oxide (NO) production and the expression of a selected panel of immune-response-related genes in LPS-stimulated RAW 264.7 macrophages was also evaluated. Fractions from both dairy by-products inhibited NO production in LPS-stimulated RAW 264.7 cells. Especially, ovine SW-D-P3 showed a strong NO inhibitory activity and suppressed inducible nitric oxide synthase (Nos2) mRNA levels. However, YAW-D-P3 could not trigger neither the gene expression of inflammatory macrophage mediators Nos2 and cyclooxygenase-2 (Ptgs2) nor tumor necrosis factor-α (Tnf) and interleukin 6 (Il6) in LPS-stimulated murine macrophages regardless of animal origin. These findings suggest that in vitro digestion could enhance the production of ACE-inhibitory peptides in both dairy by-products, while SW from ovine origin displays higher potential as an anti-inflammatory agent, effectively preventing excessive NO production.

Inhibition of nitric oxide production in RAW 264.7 cells and cytokines IL-1β in osteoarthritis rat models of 70 % ethanol extract of Arcangelisia flava (L.) merr stems

IntroductionOne of the most frequent types of arthritis is osteoarthritis, also referred to as a degenerative joint disease. Interleukin-1β (IL-1β) and nitric oxide (NO) are essential factors in the pain response; IL-1β and NO are responsible for increasing the production of matrix metalloproteinases (MMP) and a disintegrin-like and metalloproteinases with thrombospondin motifs (ADAMS) in chondrocytes. Arcangelisia flava (L.) Merr. Has been traditionally used to treat jaundice, liver disease, diarrhea, fever, and inflammation. MethodsThis study used in vitro and in vivo models to determine the effect of a 70 % ethanol extract of Arcangelisia flava (L.) Merr. stems on the inhibition of NO production in RAW 264.7 cells induced with lipopolysaccharide (LPS) and IL-1β in osteoarthritis rats induced with monosodium iodoacetate (MIA). The NO inhibition test was determined by the NO colorimetric assay using Griess reagent and measured by the ELISA plate reader. The measurement of joint diameter and hyperalgesia in osteoarthritis rats was carried out once a week for 7 weeks, and then the IL-1β levels were measured at weeks 3 and 7. ResultThe viability of cell line this extract was greater than 80 %, and the extract at 25, 50, and 100 μg/mL significantly inhibited NO production (p < 0.0001) in RAW 264.7 cells induced with LPS. Meanwhile, this extract at 10, 30, and 90 mg/200g BW increased latency time, reduced joint swelling, and reduced IL-1β levels in the serum in the osteoarthritis rat model. Conclusion70 % ethanol extract of Arcangelisia flava (L.) Merr. Has the potential to be an anti-osteoarthritis drug.

Ameliorative Effects of HT074-Inula and Paeonia Extract Mixture on Acute Reflux Esophagitis in Rats via Antioxidative Activity.

HT074, a multiherbal mixture containing extracts from Inula britannica flowers and Paeonia lactiflora roots, is used in Korean medicine for gastric disorders. This study investigated the protective mechanisms of HT074 against acute reflux esophagitis (RE) in rats. Nitric oxide (NO) production and mRNA expression of antioxidant-related genes (Nrf2, HO-1, SOD, CAT, and GPx2) were evaluated in LPS-induced RAW 264.7 cells. Gastroesophageal reflux (GER) was induced in rats, followed by HT074 (100, 300 mg/kg) or ranitidine (50 mg/kg) administration. Esophageal damage and histological changes were assessed. Gastric pH and protein expression levels of Nrf2, HO-1, SOD, CAT, and GPx-1/2 were measured. HT074 pretreatment reduced NO production and increased the expression of HO-1, CAT, and GPx2 in LPS-induced RAW 264.7 cells. In GER-induced rats, HT074 significantly decreased esophageal lesions and increased the expression of HO-1, SOD, GPx-1/2, and Nrf2. HT074 did not affect gastric pH. These findings suggest that HT074 protects against GER-induced esophagitis by inhibiting NO production and enhancing antioxidant activity. Therefore, HT074 could be a promising therapeutic agent for GER disease.

Characterization of Sesquiterpene Dimers from the Flowers of Inula japonica and the Structural Revisions of Related Compounds.

Sesquiterpene dimers are mainly found in the Asteraceae family. However, conflicting reports on the structures of these compounds can be found in the literature. Herein, we describe ten sesquiterpene dimers isolated from the flowers of Inula japonica, including configurational revisions of japonicone H (1-1), japonicone D (2-1), inulanolide A (4-1), japonicone X (5-1), and inulanolide F (5-2) to compounds 1, 2, 4, and 5, respectively. Five new related metabolites (3 and 6-9) are also described. Application of GIAO NMR/DP4+ analyses and ECD/OR calculations enabled us to revise the absolute configurations of an additional 13 sesquiterpene dimers isolated from plants of the genus Inula. Compounds 1, 2, 4, and 6 exhibited inhibition of nitric oxide production in lipopolysaccharide activated RAW264.7 macrophages with IC50 values of 4.07-10.00 μM.

Nitric oxide production inhibitors from Vietnamese Scutellaria indica: An in vitro and in silico study

Nitric oxide production inhibitors from Vietnamese <i>Scutellaria indica</i>: An in vitro and in silico study

Anti-inflammatory effect of covalent PPARγ ligands that have a hybrid structure of GW9662 and a food-derived cinnamic acid derivative

ABSTRACT Peroxisome proliferator-activated receptor γ (PPARγ) belongs to the nuclear receptor superfamily and is involved in the inflammatory process. Previously, we synthesized the ligands of PPARγ that possess the hybrid structure of a food-derived cinnamic acid derivative (CA) and GW9662, an irreversible PPARγ antagonist. These ligands activate the transcription of PPARγ through the covalent bond formation with the Cys285 residue of PPARγ, whereas their anti-inflammatory effect has not been examined yet. Here, we show the anti-inflammatory effect of the covalent PPARγ ligands in RAW264 cells, murine macrophage-like cells. GW9662 suppressed the production of nitric oxide (NO) stimulated by lipopolysaccharide and exerted a synergistic effect in combination with CA. The compounds bearing their hybrid structure dramatically inhibited NO production and transcription of proinflammatory cytokines. A comparison study suggested that the 2-chloro-5-nitrobenzoyl group of the ligands is important for anti-inflammation. Furthermore, we synthesized an alkyne-tagged analogue that becomes an activity-based probe for future mechanistic study.

Endurance exercise boosts Sirtuin 1 and PGC1α in mouse skeletal muscle amid nitric oxide synthesis inhibition

Abstract Sarcopenia is an age-related condition characterised by muscle atrophy and loss of muscle mass. The degradation of myofibrils (atrophy) caused by the activation of myofibrillar degradation proteins, e.g. due to a decrease in nitric oxide (NO) associated with aging, contributes to sarcopenia. NO is involved in glucose and lipid metabolism and mitochondrial proliferation; however, whether endurance exercise increases NO production remains unclear. Therefore, in this study, we examined whether endurance exercise promotes metabolic signalling in muscles during continuous suppression of NO production. Mice were assigned to three groups: control, nitric oxide synthase inhibitor administration (L-NAME), and L-NAME administration plus endurance exercise (L-NAME + Ex). The L-NAME group was administered an NO synthesis inhibitor, and the L-NAME + Ex group was administered the inhibitor and performed exercise. The relative amounts of calmodulin (CaM) and nitric oxide synthase (nNOS) in the soleus muscle were significantly increased in the L-NAME + Ex group compared with those in the control and L-NAME groups. In addition, the relative amounts of Sirtuin 1 (Sirt1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) in the L-NAME + Ex group were significantly higher than those in the L-NAME group and similar to those in the control group. CaM and nNOS are involved in NO production, whereas Sirt1 and PGC1α play facilitatory roles in glucose and lipid metabolism. These findings suggest that endurance exercise may enhance muscle metabolic signalling by increasing NO production, even with the suppression of NO synthesis.